1. Field of the Invention
The present invention relates to an ink jet printer having an ink jet head for injecting ink onto printing paper to carry out printing.
2. Description of Related Art
In recent years, an on-demand type ink jet printer has been in use because it has various advantages such as high printing speed, low noise, easy color printing, simple construction, and low price. An ink jet printer of this type includes an ink jet head provided at its front end with a plurality of nozzles arranged vertically. The ink jet head is adapted to slide along a guide bar extending parallel to a platen. Liquid ink particles are ejected from selected nozzles as appropriate for the print task as the ink jet head slides along the guide bar to thereby carry out printing on the printing paper set on the platen.
In such a conventional ink jet printer, there is the possibility of a stain or blot caused by ink residue attached to the nozzles of the ink jet head or a clogging of the nozzles that results in a reduction in the print quality. To cope with this disadvantage, it has been proposed to provide a special mechanism for cleaning the ink jet head as disclosed in U.S. Pat. No. 4,571,601, for example. This cleaning mechanism is provided with a wiping member such as paper, cloth or rubber member for wiping off the residue attached to the nozzles of the ink jet head. Thus, the nozzles of the ink jet head are cleaned periodically or as required by the cleaning mechanism.
However, in this prior art ink jet printer employing the cleaning mechanism, the wiping member also becomes dirty and must therefore be replaced by a new wiping member. Accordingly, the operator must carry out the troublesome task of replacing the wiping member. Further, because the cleaning mechanism is provided independently of the printing mechanism, the overall structure of the printer is complicated causing an increase in cost.
Further, to confirm whether of the cleaning is satisfactory, it is necessary to actually execute printing following the cleaning. In this circumstance, a test print is carried out on printing paper, after ending the cleaning, to confirm whether the result of the cleaning is satisfactory, that is, whether characters are properly printed. Accordingly, not only is the wiping member wastefully used but so too is the printing paper for the test print thereby uneconomically increasing operating costs.